Coking retort oven with liner walls of two thicknesses



Spt- 3, 1963 1 G. TUCKER, JR 3,102,846

COKING RETORT OVEN WITH LINER WALLS OF TWO THICKNESSES Filed April 20, 1961 5 Sheets-Sheet Sept. 3, 196.3 L. G. TUCKER, JR

COKING RETORT OVEN WITH LINER WALLS OF TWO THICKNESSES Filled April 20, 1961 5 Shests-Sheet 2 Sept. 3, 1963 L, G. TUCKER, JR 3,102,846

COKING RETORT ovEN WITH LINER WALLS oF Two THICKNEssEs Filed April 2o, 1961 5 sheets-Sheet s f Ag@ JNVENTOR.

BY Kiwa @co 8M, fr; T rade/JE, Y'

Sept. 3, 1963 L. G. TUCKER, JR

COKING RETORT OVEN WITH LINER WALLS OF' TWO THICKNESSES Filed April 20, 1961 5 Sheets-Sheet 4 21 ALTERNATE. ,.ff` couzsf. ,-NINTLEMLDIATL T'dl.

Sept. 3, 1963 L, G, TUCKER, JR 3,102,846

COKING RETORT ovEN WITH LINER WALLS oF Two THICKNESSES Filed April 20, 1961 5 Sheets-Sheet 5 gzl.

INVENTOR. L z/v ooo S750/5ft United States Patent O 3,102,846 CUKING RETORT @VEN WITH LINER WALLS F TWO TEHCKNESSES Linwood G. Tucker, Jr., Pittsburgh, Pa., assignor to K'oppcrs Company, Inc., a corporation of Delaware Filed Apr. 29, 1961, Ser. No. 104,280 6 Claims. (Cl. 2in- 139) The present invention relates in general to improvements in the liner wall structure :of horizontal coke oven batteries of the general type of H. Koppers U.S. Patent No. 818,033, in which the heating walls are arranged Iside by side in a row, in alternation with intervening coking chambers, with each heating wall constituted to a single row of vertical combustion ues extending crosswise of the battery, for simultaneous heat- .ing of both the coking chambers along each side of the heating walls. In such coke oven batteries, it is now, and for a long time has been, customary to make the heating walls and the oven chamber top and bottom walls of silica brick with highly silicious mortar joints, as explained in Rueckel U.S. Patent No. 2,393,658 of January 29, 1946, and to standardize the thickness of the `liner walls in the range 3 to 5" thickness.

However, `due to the later-a1 pressure that might be exerted on the liner Walls by the coal charges in the coking chambers, and the load imposed on said walls, las a result of loaded larry cars running on rails along the battery roof, the liner walls have been, in practice, limited to 4 and 5 Walls, to insure against `damage to the structure for the normal life expectancy of such commercial ovens.

Coke oven builders have continually been looking for ways to increase the throughput of coke ovens and yet retain the Vfeatures of the structure by virtue of which they have lasted long enough to carbonize in some cases three to four hundred thousand tons of coal per oven. Any increase in coking rate will reduce the initial investment that steel producers will be called upon to make per -unit of coke and hence per unit of steel produced. The steel industry will be very receptive to a method of this type which will enable them to reduce the cost of coke in new batteries of coke ovens built .for increased production as well as for batteries built to replace worn out or obsolete units.

One method of increasing the coal carbonizing rate of coke ovens is to increase the rate of heat transfer through the oven walls. With the present design of ovens, the limiting factor in regard to heat transfer is the restricting temperature that can be carried in the combustion chambers. The rate of heat transfer can be increased by designing thinner wall brick liners, but if liners are made thinner than 4", the strength of the oven wall is reduced, making this attack impractical.

The primary object of the invention is the improvement of the liner wall structure of these vertical ues in -a manner providing for heat transfer therethrough at the faster rate corresponding, for instance, to that of a 3" wall, as compared with a 4 thick wall, ora 4" wall as compared with a 5 wall, but Which provides additional structural strength to such walls corresponding to that aitorded by a 4" and 5 thick wall respectively. More particularly, the aim of the invention is to provide a mode of construction of such heating walls meeting the long-sought desire, and `satisfying the present urgent demand for an increase in `the rate of coking -to increase the coking capacity of oven chambers, in a manner retaining the single row vertical combustion flue type of heating walls for safe coking operation in coke oven batteries as aforesaid, by providing them with liner walls having the faster heat `transfer rate available with ICC a thinner liner wall of a thickness of 3" to 4", but with the strength of walls of 4 to 7" thickness.

In accordance with the present invention, it is believed that the rate of heat transfer can be safely increased While strengthening the wall structure by designing the brickwork with protruding liner portions, as illustrated in the drawings, utilizing 21/2 to 41/2 brick -in alternate courses, layers or strata and 5 to 8 brick in the intermediate courses, layers or strata of the liner walls, between and joined to the brick in the tie walls. Actually, the strength of the wall as a whole should be increased as a result of the novel design, because of the strong ceramic bond that will be :obtained between the mortar and the brickwork of the protruding portion of the liners. This type of strong ceramic bond is observed during the tear down of old batteries. The bottle brick for air land gas at the base of the heating ilues that have been heated to the higher temperatures `are strongly bonded together whereas the liner brick Iare very weakly bonded. Also the bottle brick appear to be stronger because of the higher temperatures. The non-protruding liners in the present invention should also be more strongly bonded than with the conventional non-protruding liners because a larger percentage of the area of the motar joints will be heated to the higher temperature. For example, assume the oven wall is made up of liners 3 and 5" thick, alternately spaced up the entire height of the vertical due. The 5" liner would project 2 Within the flue. Therefore, this entire -projection should approach the temperature of the flue surface side of the 3 liner. It would be unwise to make this projection lmuch greater than 2 because it would then interfere with the combustion and ilow of gases up the llue and therefore it would not approach the temperature level of the hot side of the 3 liner. Because the entire projecting portion of the liner approaches the temperature of the 3 liner the heat transferred through the wall would be about the same as if all the liners were 3" in thickness.

The entire exposed portion yof the wider 5" liners would be raised to the maximum flue temperature. Under these conditions, the brick not only would have its maximum strength because of its crystalline structure change but the brick and mortar will be bonded firmly at these temperatures. Because a larger portion of the oven wall brickwork has been strengthened and bonded due to this elevated temperature, the oven wall is naturally stronger. Based on these facts the strength of a `wall of this design would be stronger than .a 4 wall Iof uniform `liner thickness. So, too, with -a liner wall formed of 4 and 5'l or 4 and 6'I wide bricks in alternate courses.

Assuming a liner wall is built in whole or in part of alternate 3" and intermediate 5" liners as illustrated in FIGURES 1 and 2, practically the entire protruding section of the 5 liner would be at a temperature approaching the airport brick. Based on this assumption, the vertical isotherm should be similar to the one illustrated in 'FIGURE 3, which indicates a liner wall of this design should have a heat transfer rate equivalent to a conventional wall that is slightly over 3" thick. Studies have been made and data obtained which show that the coking rate can be increased substantially by reducing the average liner wall thickness from 41/2 inches to 3 inches.

In general it is recognized that all heating Walls of all coke ovens are not built exactly because many must contain certain design features that reduce the rate of heat transfer in order to strengthen the walls which are expected to also be affected by factors such as the carbonization pressure tof specific coals that are to be carbonized and other variables. In practice, the thickness .of the liner-` walls has usually been limited to 4" and 5 liner walls,

ating rates and procedures, would be limited. These 4 t and 5" liner walls reduce the coke capacity of the cokeproducing unit, although it is recognized that if substantial parts of the liner wall could be built with a thickness of, say, 3", the heat transfer would be -appreciably improved.

By embodying the principles of the present invention, a substantial proportion, as illustrated in the drawings, of the liner wall can be built with a thickness `of 3 without sacrificing the strength of the wall, even though the remaining tiers or courses may be, although not necessarily, thickerth'an is conventional. Actually, the strength of the wall will be increased because of the strong ceramic bond between the mortar of the protruding portions of the liner brick and the bricks adjoining them in the tie walls.

In accordance with the present invention, the heating walls of coking chambers are built -in the customary manner of silica brick masonry in tiers or courses with silica mortar joints to form oppositely disposed liner wall portions and transverse tie wall p ortions but with the alternate tiers of brick of ya thickness between 21/2 and 41/2 inches and the intermediate tiers of brick 5" to 8" thick so that a portion of 21/2 to 3% inches protrudes into the liue chamber and `extends from one tie wall to the next tie wall. With this arrangement, the heat of the gases in the iiue bonds the protruding portions to the adjacent brick in the tie walls as well as to adjacent bricks in the liner walls to form a strong ceramic bond as mentioned aforesaid. The protruding portions should not exceed 21/2 to 31/2 inches, since otherwise the heat transfer rate through the thicker brick would not correspond with the rate of heat transfer through the thinner brick in the alternate tiers or courses. Thus, the measure of protrudement is limited to that extent to which the protruding brick will have the same rate `of heat transfer as the thinner liner wall portions. Such a wall then will have the average strength of a 4 to 7 inch wall with a rate of heat transfer of a 3 to 4 inch wall.

This type of wall structure is especially suitable to use with the three most generally used types of heating walls now most generally used in the building and operating of horizontal coking retort ovens in the United States as well as in many foreign countries.

In addition to the features recited above, the invention has for further objects such other improvements and advantages in construction, arrangements, and operation hereinafter ldescribed and claimed. i

The features of faster coking with the liner wall structure according to the present invention is best performed,

and therefore carried out in its preferred form, in the manner of Patent No. 2,447,837 tof 1948, of Joseph Becker, in conjunction with the flue bottom regulation of his Patent No. 2,100,762, in order to retain and accentuate the advantages of low pressure dierential around thek heating flue system that accrues with the greater freedom from counterflow conditions of its cross-over system, with the uniform coking aiforded in conjunction with the faster coking of the present invention. l

The novel `features of the invention, however, are not limited in all their aspects to conjoint use with the aforesaid features, since the novel features are equally applicable to other types of heating iue systems, such as the twin flue, double divided, high and low burner ues, or other ilued systems, such as that of Koppers Patent No. 818,033, Totzek Patent No. 1,782,638, and Otto Patent No. 2,665,442. For convenience, the present description of the invention will be confined to use of the invention in `ovens :of the type described in said patents.

The accompanying drawings, forming a part of this specification, show for purposes of exempliiication, a preferred form and manner in whichthe invention may be embodied and practiced in the ovens of said patents, but

the invention is not to be limited to such illustrative instance or instances.

FIGURE 1 is an enlarged horizontal sectional view of coke oven iiues and flue wall taken on the line I-I of FIGURE 2; p

FIGURE 2 is -a vertical cross-sectional view taken on the line lI--II of FIGURE 1;

FIGURE 3 is a diagrammatic isotherm view of ovenflue wall;

FIGURE 4 is `a view showing fa vertical section taken i longitudinally through a horizontal coke oven battery of the Becker type of the aforesaid Patent No. 2,100,762, and provided with the present liner wall improvement of their coking chambers and heating walls;

FIGURE 5 lis an enlarged horizontal view taken on the line V-V of FIGURE 4 'and showing the heating `iiues tand structural detail of the masonry of one heating tof Totzek U.S. Patent No. 1,782,768, the View being taken i on the line VII-VII of FIGURE 8;

FIGURE 8 is a plan section taken on the line VIII- VIIIV of FIGURE 7;

FIGURE 9 is a plan view of an intermediate course B 'as shown in `FIGURE 7;

FIGURE 10 isa plan view of an alternate course A las shown in FIGURE 7;

FIGURES l1 to 14 are views similar to FIGURES 7 to 10, illustrating the Wilputte type of `oven with brickwork tofthe type of Otto U.S. Patent No. 2,665,242;

FIGURES 15 to 18 are views similar to FIGURES 7 to 10 but illustrating the Otto type of oven with the brickwork of the same Otto Patent No. 2,665,242.

The same characters `of reference designate the same parts in each of the views of the drawings.

In the embodiments illustrated in FIGURES 1 to 6 of the drawings, the invention is incorporated in a combination Koppers-Becker coke oven battery; that is, a battery having provision for :being fired alternatively with an extraneously derived relatively lean tgas, such as producer gas `and blast furnace gas, or with la relatively rich gas such `as coke oven gas. For convenience, the present 'description will be confined to the present illustrated embodiment of the invention in such la combination oven battery; features of the invention may tbe applied, bowever, to other structures, for example, toordinary socalled coke ovens tired with coke oven gas, or ordinary so-called gas ovens tired with producer' `gas br blast furnace gas; hence, the invention is notv coniined in its scope to the combination oven `or to` the specific ruse and specific embodiment in a cross-over iiue type oven herein described as an illustrative example.

As the present improvements are useful with various types of coking retort ovens such as those shown in FIG- URES 7 to 18, and as the details of such ovens may be readily understood by reference to the aforesaid patents which l:are made a descriptive .part hereof, a brief description of the various parts `of an oven battery that are concerned with the present improvements will suffice for an understanding of the same.

In general, a coking retort oven battery comprises high and narrow coking chambers `1l() tapered asshown in FIGURE 5 to increase in width from one horizontal end 10a, at which -a pusher ram is inserted, to the opposite horizontal end 10b, at which the coke is discharged out of the oven chambers, tand tare provided as usual with coke oven doors (not shown) at these opposite ends.

Heating walls 11 yare provided on two opposite sides of the oven chambers l10 throughout the length and height v forethe surface of their contacts with the mortar.

of the same, and the heating `walls 11 are constituted of combustion iiues 12 for llame heating charges in the adjacent chambers.

The heating walls 11 are formed of refractory silica brickwork and each comprise l-iner walls .13 on opposite sides .thereof disposed between .the vertical combustion chamber spaces 12 in the heating walls l11 and the coking chamber space of the chamber in the Iform of a slot intermediate the heating walls.

The liner walls yform the side :faces of the looking cham- -bers 10 and conduct the heat 4from ames of combustion in the vertical combustion ues `12 formed by the-tie walls 20 directly into coal charges in the oven chambers 10 laterally inwardly of their mass from the two opposite sides thereof.

The heating walls 11 are .constructed in ygeneral parallelism with each other and heretofore the liner Walls 13 were constituted of the same thickness in any horizontal plane throughout the length of the coking chambers `10, usually of 4" or 5" thick bricks. Conventionally the upper and lower portions of these liner Walls are backed up with thicker brickwork 14 than the rest of the liner wallbricks 13 4to prevent overheating of the parts of the chambers 10 alongside the region of ignition in the base 1S of the combustion ues and in the region alongside the crown space 16 where the distillate gas ows along the top charge of coal during coking, and in such case the brickwork was of uniform thickness in any horizontal plane of such .portions of the heating wall all along the coking chamber.

The coking chambers of a coke loven battery are each formed between a spaced pair of flued heating walls of which the masonry comprises, in most modern coke ovens, silica bricks laid in ymortar in courses or tiers. The individual bricks of each tier or course, and those of adjacent tiers, are joined by a layer of special mortar 18 having a refractoriness only slightly less than that of the bricks themselves. The material of the silica bricks has a Pyrometric `Cone Equivalent (hereinafter referred to las P.C.E.) of about 300D-3056o F. and shows upon chemical :analysis a content of approximately 95 to 96% of silica, 2% of lime, and about 2% of such so-called impurities `as iron oxide, alumina, 'and the like. The mortar or cement in which they are customarily set is prepared from .silica brickbats, vraw 'ganisteig and a silicious clay, the finished mortar containing 92% to `94% of silica, and from 6% to 8% of alumina, iron oxide, lime, etc., and having la P.C.E. of between about 2940 to 3000 F. The P.C.E. of the mortar wherein the silica bricks are set has thus a P.C.E. of not more than about 100 IF. lower than the bricks themselves.

If the temperatures of the heating-wall masonry are raised to about 26002700 F., a relatively rapid recrystallization of silica in the mortar as well as that in the bricks begins to take place and crystal growths, extending therebetween and involving forms of silica in the both, are produced and the bricks and mortar become thereby so securely bonded together tha-t the structure of the brick, themselves, frequently yields under stress be- The extent of such bond follows rather closely the isothermal lines of 26002700 F. in the heating wall.

In accordance with the present invention, the alternate tiers or courses `21 and intermediate tiers or courses 19 of liner bricks that form the liner wall portions 13 between the tie walls 20 are composed, throughout substantially the full height of the combustion iiues, of dilerent thickness, the alternate tiers or courses 21 being 21/2 to 41/2 inch brick and the intermediate -tiers 19 being 5 to 8 inch brick, and a mortar joint 18 being provided between the ticwall 20 surface and the adjacent surface of the inwardly projecting 21/2 to 31/2 inches of the 5" to 8" liner brick. t

The many benefits that accrue from the present invenltion are attained in a better way with the horizontal coking chamber 10 arranged in a battery with vertical combustion ues 12, as indicated in FIGURES 4 and 5, wherein each horizontal slot chamber 10 and its heating walls 11 are in the form of a battery of a series of alternate coking chambers with a heating wall 11 intermediate each two coking chambers 10 arranged side-by-side in a row. As shown, the liner walls 13 are interconnected, as conventionally, by tie walls 20, which together with the liner walls 13, form the vertical combustion flues 12.

`The 5" to 8" brick of the intermediate tiers 19 along the upper half of the ilues 12 that are in the portion of the liner walls 13 between each two tie walls 20, project inwardly into the vertical ues about 21/2 to 31/2 inches, and their side faces are united to the faces of the ytie walls 20 by mortar joints 18, as above described. As is shown in FIGURES 4 and 5 the outer surface of each :liner Wall 13 forming a face for the coking chamber 10 adjacent thereto is substantially a plane surface while the inner surface (due side) of each liner wall 13 is a furrowed or corrugated surface in which the thicker intermediate tiers 19 appear in FIGURE 4 as a series of alternating horizontally extending ribs and valleys.

Each flue 12 is provided at its lower end with -a pair of regenerator ports 22, and an inlet nozzle 23 for rich gas, and a pair of crosswise regenerators 24, and 25, are connected with each ue through their regenerator ports as conventional for combination oven underring.`

Referring to FIGURES 7 to 18, there is shown the manner in which the invention may be utilized in conjunction with the standard brick shapes as used in construction of the three rnost generally used types of coke ovens.

FIGURES 7 to l0 illustrate the shapes of the bricks, and their employment in conjunction with the present invention, as used in the standard Koppers-Becker and also the H. Koppers ovens. In these drawings 10 indicates the coking chambers, 11 the heating wall between them, and 12 is the combustion line between two tie walls 20. The liner walls 13 are comprised of alternate courses or tiers 21 and intermediate courses or tiers 19. Numeral 26 indicates the regenerator ducts and 27 the horizontal flue. The bricks are of the type illustrated in Totzek Patent No. 1,782,638. In this type of coking retort oven, each tier is composed of two spaced courses of liner or stretcher brick 40 and an interposed connecting course of tie or header brick 41. The liner brick 40 have recesses `42 at their inner faces `for interlocking with the tie brick 41.

i The tie brick 41 alternate with the liner brick 40 in each course. The tie brick 41 have the shape of a hammerhead 41a which is joined to a transverse brick 41b. The

`harnmerheads 41a for the tie wall 20 alternate in position in the courses on opposite sides of the heating wall 11. The limbs or transverse brick 41b are made of several 'brick as shown. The brick of the alternate tiers 21 and those of the intermediate .tiers 19 are staggered so that the hammerheads 41a are at opposite ends of adjacent tie walls 20 in each tier 19 and 21.

ln accordance with the present invention, the liner brick in the intermediate tiers 19 are of greatest thickness so as to protrude into the iiue chamber 12, between each two tie walls, for 21/2 to 31/2 inches. As a consequence, the protruding portions 40C of the liner brick of the intermediate tiers are bonded by the heat of the combustion in the llue chambers 12 to the adjacent bricks of the same tier in the -tie walls, through crystallization of the silica mortar of the vertical joints 43, and also likewise bonded through the mortar joints 44 between these bricks and the bricks in the alternate tiers above and below the intermediate tiers, thus providing the greater strength to the wall inherent in such a bond. The protruding portions of the brick in the intermediate tiers are also exposed on three sides, 45, 46, and 47, thus heating these bricks to provide the isotherm as indicated in FIGURE 3.

FIGURES 1:1 to 14 illustrate the shapes of the bricks, and their employment in conjunction with the present andasse invention, as used in the standard Wilputte double divided ovens. In these drawings 1li likewise indicates the coking chambers, 11 the heating wall between them, and 12 is the combustionflue between two tie walls 29. The liner walls 13 are composed ofalternate courses or tiers 21 and intermediate courses or tiers 19, and 26 indicates the regenerator ducts and 27 the horizontal flue. The bricksrare of the type illustrated in lOtto US. Patent No. 2,665,242. In this type of coking retort oven, each tier is composed of `two spaced courses of liner bricks '4S and binder or cross tie bricks 49. Ihe liner bricks 48 have recesses 50 at their inner faces for interlocking with the tie brick 49. One end of each course of tie brick 49 consists of a tenon 51 extending between liner bricks 42B in the liner wall area 13 and forming'a part thereof. The adjacent superposed tie bricks v49 of the tiers are turned end for end, and have their tenori portions 1 provided with shoulders 52 which overlap the liner brick 48 at their joints. The limbs 53 of the tie brick 49 are made of several bricks. In accordance with this invention, the liner brick in the intermediate tiers 19 are of greater thickness than those in the alternate tiers 21, so as to protrude into the flue chamber area 12, between each two tie walls Z0, for 21/2 to 31/2 inches. As a consequence, the protruding portions 54 of the liner brick 4S ofthe intermediate tiers or courses 19, are bonded through crystallization of the silica mortar 18.01? the vertical joints 55, and also likewise bonded through the mortar joints S6 between these bricks 4S and the bricks 48 in the alternate tiers or courses 21 above and below the intermediate tiers, thus providing greater strength to the wall 13l inherent in such bond. The protruding portions 54 of the brick of the intermediate tiers are also exposed on the three sides, 57, 5S, and 59, thus heating these bricks to provide the isotherm as indicated in FIGURE 3.

FIGURES l5 to y18 illustrate the shapes of the bricks, and their employment in conjunction with the present invention as used in the standard `Otto twin or hairpin flue ovens. In these drawings, 1t) also indicates the coking chambers, 11 the heating wall` between them, and 12 is one limb of the hairpin combustion flue between two tie walls 20. The liner walls 13 are composed of alternate courses or tiers 21 and intermediate courses or tiers 19, and 26 indicates the regenerator ducts and 27 the hori-v zontal flow connection between adjacent limbs tor concurrent upflow in each limb `12 in alternation with the downilow in the other limb I12. 'l'he bricks are also of the type illustrated in Otto U.S. Patent No. 2,665,242. In this ltype of coking retort oven, each tier is composed of two spaced courses of liner brick 611 and binder 0r cross tie brick 61. The liner brick 6i) have recesses 62 at their inner faces for interlocking with the tie brick 61. One end of the course of tie brick consists of a tenon 63 extending between the ends of liner brick 6d in the liner area 13 and forming a part thereof. The adjacent superposed tie bricks 61 of the tiers are turned end for end, and have their tenori portions `63: provided with shoulders 65 whichoverlap the liner brick 6d at their joints. The limbs 66 of the tie brick `61 are made of several bricks. In accordance with this invention, the liner brick in the intermediate tiers 19 are of greater thickness than those in the alternate tiers 21, so as to protrude into the ue chamber area `12, between each two tie walls 26', for 21/2 to 3`1/2 inches. As a consequence, the protruding portions 67 of the liner brick 169 of the intermediate tiers or courses 19, are bonded through crystallization of the silica mortar 18 of the vertical joints 67, and also likewise bonded through the mortar joints `68 between these bricks 60 and the bricks 60 in the alternate tiers or courses 21 above and below the intermediate tiers, thus providing the greater kstrength to the wall -13 inherent in such bond. 'I'he protruding portions 67 of the brick of the intermediate tiers are also exposed on the three sides 69, T70, and 7.1, thus heating these bricks` to provide the isotherm as indicated in FIGURE 3.

The best mode yof carrying out the novel feature of the present invention to attain its benefits to greatest extent is in conjunction with the improvements of the aforesaid Patent No. 2,447,837.

Accordingly, as shown in FIGURES 4 and 5, the vertical combustion ues 7120i each heating wall 11 constructed according to the invention as aforesaid, are interconnected by cross-over `tlues and upper horizontal flow ducts 2'7, Said vertical combustion fines lterminate at their upper parts (flow ducts 27) below the top level 29 for leveled coal charges; which level 29 conventionally is the lower level of the leveler door (not shown) in the pusher ram doorway 10a through which the tops of the coal charges are leveled tto leave above the top ofy the leveled coal charge a gas oi-ilow space 16 along the crown of the oven chambers l-ti.

In this structure in accordance with the invention of Joseph Becker Patent No. 2,100,762, all regulation is at the bottom of the vertical ilues 12 by means of restrictions dor the regenerator ports 22 and the rich gas horizontal inlets 23. The areas of the vertical combustion flues 12, flow duct means 27, and cross-over hues for the vertical ilues 12 are made sufiiciently large that they have no material effect on the gas ow and in this way, the gas rflow through the flues occurs with lesser differences in pressure from inlet to outlet, and less draft is required, and the liner walls 13 are vertically disposed throughout the major portion of .their height for uniform coking vertically throughout coal charges in the coking chambers 1t).

In oper-ation, coal is charged into the oven chambers 10 through their top charging yholes in the oven roof and leveled at the top level 29, and heat is applied by combustron of gas and air 1n the vertical flues 12, to maintain substantially the same temperatures all along the heating walls 11, except at the end flues where the temperature is higher because of radiation at the opposite side faces of the battery. All the regulation is below the bottoms 15 :of the ilues and due to the two thicknesses of the liner walls `13 made feasible by, the advent of the present invention, the mass of coal is fully coked -in a shorter coking time by heat applied laterally inwardly from the sides of the` chamber. 'llhe faster coking time with the novel liner structure provides for a greater number ofvcharges of coke to be made up to 15% to 20% more than heretofor with liner walls of one thickness.

The invention, as described hereinabove, is embodied in particular form and manner but may be variously embodied within -the scope of the claims hereinafter made.

What is Kclaimed is:

l. In a horizontal coking retort oven battery, an inter-A mediatey heating wall for two adjacent horizontal coMng chambers comprising:

(a) spaced longitudinal brick liner walls,

(b) intermediate transverse tie walls tying said liner walls and dening therewith individual vertical combastion iiues inside the heating w-all, and i' (c) alternate and intermediate horizontally disposed" layers of bricks in said liner walls arranged to form an outer substantially plane surface and |an inner corrugated surface,

l(f1) the intermediate horizontally disposed layers being substantially thicker than the alternate horizontally disposed layers and projecting inwardly thereof into the vertical flues, the projecting portions thereof extending between adjacent (b) Vintermediate transverse tic walls tying together saidy linerwalls and defining therewith individual vertical Y combustion ues inside the heating wall, and

(c) alternate and intermediate horizontally disposed strata of bricks in said liner walls arranged to form outer sulbstantially plane surface and an inner corrugated surface,

(1) the alternate horizontally disposed strata having a maximum thickness in the range from about 21/2 inches torabout 41/2 inches, and "1(2) the intermediate horizontally dispo-sed strata having a maximum thickness in the range from about 5 inches to about 8 inches with portions t thereof projecting inwardly into the vertical 'ues and extending between adjacent tie walls being bonded thereto. 4. In Ia horizontal Icoking retont oven for a flue within a heating wall thereof, which ue is dened by liner walls and tie walls, liner wall yconstructitm comprising an outer substantially plane surface, an inner corrugated surface of 1i) alternating ribs and Valleys, said ribs extending from tie wall to tie wall and being Kbonded thereto.

5. Liner wall `construction substantially as recited in claim 4 wherein the ribs project a maximum of about 31/2 inches from the surface of `the'valleysI Y 6. Liner wall construction substantially as described lin claim 5 wherein the maximum thickness of the liner wall between ribs is within the range of about 2% to about 41/2 `inches and the maximum thickness of the liner wall throughthe ribs is yin the range of about 5 inches to about 8 inches.

References Cited in the file of this patent UNITED STATES PATENTS 1,044,763 Ekstrom Nov. 19, 1912 1,571,575 Darrah Feb. 2, 1926 1,705,841 Van Ackeren Mar. 19, 1929 1,989,459 Parker Jan. 29, 1935 2,960,746 Whitney Nov. 22, 1960 

1. IN A HORIZONTAL COKING RETORT OVEN BATTERY, AN INTERMEDIATE HEATING WALL FOR TWO ADJACENT HORIZONTAL COKING CHAMBERS COMPRISING: (A) SPACED LONGITUDINAL BRICK LINER WALLS, (B) INTERMEDIATE TRANSVERSE TIE WALLS TYING SAID LINER WALLS AND DEFINING THEREWITH INDIVIDUAL VERTICAL COMBUSTION FLUES INSIDE THE HEATING WALL, AND (C) ALTERNATE AND INTERMEDIATE HORIZONTALLY DISPOSED LAYERS OF BRICKS IN SAID LINER WALLS ARRANGED TO FORM AN OUTER SUBSTANTIALLY PLANE SSURFACE AND AN INNER CORRUGATED SURFACE, (1) THE INTERMEDIATE HORIZONTALLY DISPOSED LAYERS BEING SUBSTANTIALLY THICKER THAN THE ALTERNATE HORIZONTALLY DISPOSED LAYERS AND PROJECTING INWARDLY THEREOF INTO THE VERTICAL FLUES, THE PROJECTING PORTIONS THEREOF EXTENDING BETERRN ADJACENT TIE WALLS BEING BONDED THERETO. 